The present invention relates to a device for use with a display panel, and particularly for use with a flat screen display panel, which can be illuminated from the rear by means of a backlight, having a backlight control to adjust a luminance measured by a sensor to a selectable setpoint value, which represents the intensity of the backlight.
To control the luminance of a backlight for a liquid crystal display (“LCD”) panel and flat screen LCD displays, a backlight control is usually provided. This backlight control adjusts the luminance of the backlight illuminating the display panel from the rear and measured by a sensor to an essentially constant setpoint value. The drawback is that such a backlight control measures and regulates only the luminance of the backlight, while influences affecting the luminance of an image displayed on the display panel are not measured and, therefore, can not be corrected. For example, it is not possible to measure and to correspondingly correct effects that interfere with the luminance of the image due to aging of the glass, the LCD fluid, or the diffuser and/or polarization foils of the display panel.
The German application with the official file number 10323221.4 proposes to arrange transparent parts between a sensor and a backlight whose aging and temperature properties essentially correspond to those of the transparent parts of the display panel. The sensor measures the luminance of these transparent parts, which a backlight control adjusts to a selectable setpoint value, such that effects due to aging and/or the temperature of the display panel that interfere with the luminance of an image displayed on a flat screen display panel are largely avoided. The drawback is that, for example, the temperature influences within the flat screen and outside the flat screen differ, so that the luminance can only be detected imprecisely.